perf tools: Add event_update event unit type

Adding unit type 'event update' event, that stores/transfer events unit
name. The unit name is part of the perf stat output data.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Kan Liang <kan.liang@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1445784728-21732-22-git-send-email-jolsa@kernel.org
[ Rename __alloc() to __new() for consistency ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 1e843c6..6aa2b92 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -105,6 +105,9 @@
 int perf_event__synthesize_attrs(struct perf_tool *tool,
 				 struct perf_session *session,
 				 perf_event__handler_t process);
+int perf_event__synthesize_event_update_unit(struct perf_tool *tool,
+					     struct perf_evsel *evsel,
+					     perf_event__handler_t process);
 int perf_event__process_attr(struct perf_tool *tool, union perf_event *event,
 			     struct perf_evlist **pevlist);
 int perf_event__process_event_update(struct perf_tool *tool __maybe_unused,